Opinions as to the nature and origin of Christianity have been profoundly modified during rather recent years by the increased attention that has been given to the circumstances of the society within which its work was to be done. It is fortunate that these inquiries have been undertaken by scholars whose primary interest has not been to defend Christianity, but only to understand the conditions that necessarily determined its forms both of organization and of faith. Into their studies Christianity entered only as one element among many others, and it is this fact that gives to their results their peculiar value for the history of Christianity itself.